Single-source-precursor synthesis and high-temperature evolution of novel mesoporous SiVN(O)-based ceramic nanocomposites

Mesoporous SiVN(O) ceramics were prepared from a mixture consisting of VO(acac)(2)-modified perhydropolysilazane and polystyrene. The resulting amorphous single-phase SiVN(O) ceramics remained amorphous in nitrogen atmosphere up to 1400 degrees C. The as-prepared materials consist of nanoscaled vanadium nitride dispersed in amorphous Si3N4; exposure to 1600 degrees C leads to the crystallization of VN and Si3N4. The specific surface area (SSA) and the pore size of the SiVN(O)-based ceramics can be easily controlled by the temperature of thermal treatment and by the amount of polystyrene. The average pore size of the prepared SiVN(O) ceramics was 4-10 nm and their largest SSA values, 642 and 506 m(2)/g, were achieved upon ammonolysis at 800 and 1000 degrees C, respectively. The combination of metal-modified single-source precursors and encapsulated porogens provides a convenient one-pot synthesis process to prepare mesoporous ceramic nanocomposites with controllable phase compositions and morphology.